Weakfish Have you ever wanted to have shiny silver skin like the Weakfish? The Weakfish is the state fish of Delaware. The weakfish has a dark, olive green back that fades to a silvery-white belly. Weakfish can live up to 17 years old but most don’t make it past 9-12 years. The Weakfish got its name from it's fragile mouth which tears easily when hooked by anglers.